Long-term Hippocampal and Amydalar Dendritic Spine Alterations after Adolescence Psychosocial Stress

Abstract

Stress, in particularly adolescence stress has been shown to result in long-term changes in brain and behavior of humans and rodents as well as predisposing individuals to multiple neuropsychiatric disorders like depression and schizophrenia. Stress-resulting in behavioral changes are often associated with structural changes of the neuronal dendritic spines, especially of the limbic system. Thus, analyzing alterations in structure of the dendritic spines in animals, which were subjected to adolescence stress, might provide useful information on pathogenesis of mental disorders. Herein, we analyzed the length, head width and area of dendritic spines of neurons from the hippocampal CA3, the central amygdala and the basolateral amygdala (BLA) regions in mature C57BL/6 mice, which were subjected to adolescent psychosocial stress. Results showed that stressed animals had longer spines in the hippocampus, larger spines in the BLA and shorter, smaller spines in the central amygdala (CeA). The latter finding is particularly intriguing, as it has been shown that central amygdala is not just the relay center for signals from the BLA in fear response, but is involved in antagonistic and inhibitory function to the BLA and active in appetitive and reward pathways.